The present disclosure relates to a motor assembly and a method for controlling the motor assembly. The motor assembly is characterized by comprising: a stator having a plurality of slots; a first coil and a second coil isolated from the first coil, the first and second coils being wound on each of the plurality of slots such that three-phase alternating currents are applied thereto; a rotor rotated by rotation magnetic fields generated by the first coil and the second coil; a first inverter unit for controlling the three-phase alternating current which is applied to the first coil in order to generate the rotation magnetic field; and a second inverter unit for controlling the three-phase alternating current which is applied to the second coil in order to generate the rotation magnetic field. Control signals for turning on and off the three-phase alternating currents applied to the first coil and the second coil are generated so as to be left-right symmetric by the first inverter unit and the second inverter unit during a preset switching cycle.

In an example embodiment, a system includes an inverter configured to operate in at least one of a charging mode or a drive mode, a cascaded direct current (DC)-DC converter, the DC-DC converter including a first portion of the inverter and at least one controller configured to selectively couple the first portion of the inverter to a first portion of the cascaded DC-DC converter during the charging mode, and selectively couple the inverter to a second portion of the cascaded DC-DC converter during the drive mode.

In an example embodiment, a system includes an inverter configured to operate in at least one of a charging mode or a drive mode, a cascaded direct current (DC)-DC converter, the DC-DC converter including a first portion of the inverter and at least one controller configured to selectively couple the first portion of the inverter to a first portion of the cascaded DC-DC converter during the charging mode, and selectively couple the inverter to a second portion of the cascaded DC-DC converter during the drive mode.

A control method includes sequentially updating a next cycle pulse width modulation command for each of an upper switch and lower switch of a phase leg of a power converter according to an order defined by timing of a rising edge of the next cycle pulse width command for one of the switches relative to a rising edge of a previous cycle pulse width command for the one of the switches.

A control method includes sequentially updating a next cycle pulse width modulation command for each of an upper switch and lower switch of a phase leg of a power converter according to an order defined by timing of a rising edge of the next cycle pulse width command for one of the switches relative to a rising edge of a previous cycle pulse width command for the one of the switches.

The invention relates to a method for operating an electric machine (100) having a stator having stator windings and a rotor, having a converter (110) and having a sensor (120) for detecting a measurement value, wherein the converter (110) has direct current connections, alternating current connections and semiconductor switches for connecting one of the direct current connections to one of the alternating current connections in each case, wherein the stator windings are connected to the alternating current connections, the semiconductor switches of the converter (110) being closed and opened at specific changeover times, a measurement being carried out by the sensor (120) at specific measurement times, the specific changeover times being adapted to the specific measurement times such that in a specific time interval about a specific measurement time the semiconductor switches are not closed and opened, and a control unit (150) and a computer program for carrying out said method.

The invention relates to a method for operating an electric machine (100) having a stator having stator windings and a rotor, having a converter (110) and having a sensor (120) for detecting a measurement value, wherein the converter (110) has direct current connections, alternating current connections and semiconductor switches for connecting one of the direct current connections to one of the alternating current connections in each case, wherein the stator windings are connected to the alternating current connections, the semiconductor switches of the converter (110) being closed and opened at specific changeover times, a measurement being carried out by the sensor (120) at specific measurement times, the specific changeover times being adapted to the specific measurement times such that in a specific time interval about a specific measurement time the semiconductor switches are not closed and opened, and a control unit (150) and a computer program for carrying out said method.

The vibration and noise generated in a permanent magnet synchronous motor are effectively suppressed. A motor control device 1 comprises: a triangular wave generation unit 17 which generates a triangular wave signal Tr that is a carrier wave, a carrier frequency adjustment unit 16 which adjusts a carrier frequency fc that represents a frequency of the triangular wave signal Tr, and a gate signal generation unit 18 which performs pulse-width modulation on three-phase voltage commands Vu*, Vv*, Vw* according to a torque command T* using the triangular wave signal Tr, thereby generating a gate signal for controlling an operation of an inverter. The carrier frequency adjustment unit 16 adjusts the carrier frequency fc so as to change a voltage phase error Δθv representing a phase difference of the three-phase voltage commands Vu*, Vv*, Vw* and the triangular wave signal Tr based on the torque command T*, and a rotation speed ωr of a motor.

The vibration and noise generated in a permanent magnet synchronous motor are effectively suppressed. A motor control device 1 comprises: a triangular wave generation unit 17 which generates a triangular wave signal Tr that is a carrier wave, a carrier frequency adjustment unit 16 which adjusts a carrier frequency fc that represents a frequency of the triangular wave signal Tr, and a gate signal generation unit 18 which performs pulse-width modulation on three-phase voltage commands Vu*, Vv*, Vw* according to a torque command T* using the triangular wave signal Tr, thereby generating a gate signal for controlling an operation of an inverter. The carrier frequency adjustment unit 16 adjusts the carrier frequency fc so as to change a voltage phase error Δθv representing a phase difference of the three-phase voltage commands Vu*, Vv*, Vw* and the triangular wave signal Tr based on the torque command T*, and a rotation speed ωr of a motor.

Selectable current limiting for a power tool. One embodiment provides a method for selectable current limiting for a power tool including determining, using a current sensor, an average current and determining whether the average current exceeds a predetermined current threshold. The method also includes determining a deviation of the average current from the predetermined current threshold and reducing a PWM duty ratio proportional to the deviation of the average current from the predetermined current threshold. The PWM duty ratio corresponds to a PWM signal provided to an inverter bridge.